A 30 year old man presents with 6 month history of nasal discharge, facial pain and fever. On antibiotic therapy, fever subsided. After 1 month again had symptoms of mucopurulent discharge from the middle meatus and the mucosa of the meatus appeared congested and oedematous. Next best investigation would be:

B i.e., Non contrast CT for nose & paranasal sinuses Bacterial sinusitis is uncommon in patients whose symptoms have lasted for > 7days. This diagnosis is reserved for patients with purulent nasal discharge and persistent symptoms (i.e. symptoms lasting > 7 days in adults or > 10-14 days in children). CT or sinus radiography is not recommended in routine cases, paicularly early in course of disease (< 7 days) d/t high prevalence of acute viral rhinosinusitis. However, CT (noncontrast) of sinuses is the radiological investigation of choice in evaluation of persistent, recurrent, or chronic (lasting > 12 weeks) sinusitisQ. Pott's puffy tumor is advanced frontal sinusitis with soft tissue swelling & pitting edema over frontal bone d/ t communicating subperiosteal abscess.